PROJECT SUMMARY/ABSTRACT Moderate or low-risk alcohol consumption (defined by the NIAAA as ?4 drinks on any single day AND ?14 drinks per week for men or ?3 drinks on any single day AND ?7 drinks per week for non-pregnant women) has been associated with a wide variety of health outcomes in both positive and negative directions. These associations have sparked incredible controversy, largely because definitive evidence about its health effects has been lacking. As a result, guidelines about alcohol use diverge dramatically from each other. In response to this ongoing controversy, and in collaboration with NIAAA, we recently initiated a large-scale, global, long-term randomized trial of daily alcohol consumption, entitled the Moderate Alcohol and Cardiovascular Health Trial (MACH15; U10AA025286). The trial will randomize nearly 8,000 adults at advanced cardiovascular risk to either consumption of 15 grams of alcohol daily in their beverage of choice or to complete abstention for six years. The trial will eventually comprise some 16 field centers and four coordinating centers situated worldwide, including a biospecimen repository to foster future research. In this application, we propose a unique symposium model that will maximize the transparency of the trial, regularly expand the reach of the study and its pool of ancillary investigators, and foster collaboration and data access to the larger biomedical community in accord with the Plan for Increasing Access to Scientific Publications and Digital Scientific Data from NIH Funded Scientific Research. Specifically, we propose to hold an annual symposium that will open the regular operational meetings of MACH15 investigators to attendees at large, content-concordant scientific conferences. This approach will 1) allow external investigators to observe trial operations and bring outside expertise to identified challenges; 2) encourage external investigators to propose new measurements [either study-wide or in site-specific ancillary studies] in real time during the trial; 3) share preliminary results related to trial process and operation with the larger scientific community; 4) familiarize trainees and junior investigators with the data elements available in MACH15; 5) recruit junior and senior investigators with limited experience in alcohol-related investigation to participate in the study of the health effects of alcohol; and 6) disseminate the trial?s ongoing conduct and opportunities to diverse sites and scientists worldwide. With this new yet generalizable model, we will convene the core MACH15 investigators, who bring some of the most extensive experience in both alcohol feeding studies and complex clinical trials worldwide, and share their expertise and resources with investigators, clinicians, policymakers, and trainees on a global basis.